Restoring soil health to reduce irrigation demand and buffer the impacts of drought     

Rebecca SCHNEIDER  Stephen MORREALE  Zhigang LI  Erin MENZIES PLUER  Kirsten KURTZ  Xilu NI  Cuiping WANG  Changxiao LI  Harold VAN ES 《农业科学与工程前沿(英文版)》2020,7(3):339

Irrigation consumes three quarters of global water withdrawals each year. Strategies are needed to reduce irrigation water use, including increasing the efficiency of transfer methods and field application. Comprehensive restoration of soil health, specifically through organic matter amendments, can substantially reduce irrigation demand and increase crop yield. A program to restore severely degraded and desertified soils by incorporating coarse woodchips into the soil successfully increased rainfall capture and elevated soil moisture for several weeks between rainfall events at both Ningxia, north-west China and North Dakota, USA. With addition of fertilizer, woodchip incorporation further increased growth of wheat and alfalfa. Comprehensive soil health assessment of remnant grasslands was used to develop target reference soil profiles by which to guide restoration efforts. Given that most agricultural soils are degraded to some degree, soil health restoration can provide a powerful strategy toward achieving global food and water security.  相似文献   

Synthesis of electrospun carbon nanofiber/WO<Subscript>3</Subscript> supported Pt,Pt/Pd and Pt/Ru catalysts for fuel cells     

Mostafa Dehghani Mobarakeh 《Fibers and Polymers》2017,18(1):95-101

In the present study, nano-sized Pt/WO₃-carbon nanofiber, Pt-Pd/WO₃-carbon nanofiber and Pt-Ru/WO₃-carbon nanofiber electrocatalysts were synthesized and the performance of prepared catalysts were compared with catalysts coated carbon black for the oxygen reduction reaction (ORR). The morphology and structure of prepared catalysts were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The SEM images showed that the catalyst nanoparticles were well dispersed on the both carbon nanofiber and carbon black supports. Electrochemical measurements including linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA) tests were applied to investigate the potential of the fabricated electrodes on the ORR. The results demonstrated that the catalysts based on carbon nanofibers showed a significant increase of activity toward the ORR. Also, the Pt/Pd coated carbon nanofibrous electrode showed the highest electrochemical activity.  相似文献   

Light transmission and the fine structure of poly(methyl methacrylate) nanofibers and films     

Maryam Mirzaei Sheshkol  Sedigheh Borhani  Mostafa Youssefi 《Fibers and Polymers》2017,18(12):2361-2367

In this paper, the structure and optical properties of poly(methyl methacrylate) (PMMA) nanofibers and films were investigated. Differential scanning calorimetery (DSC) and Wide-Angle X-ray scattering (WAXS) results confirmed the amorphous structure of both nanofibers and films. Low angle X-ray diffraction (LA-XRD) revealed the presence of voids and/or particles with the spacing of 128.4 Å within the nanofibers. From the Porod plots, a three-dimensional surface fractal for the nanofibers and a mass fractal structure for the films were derived. By the interpretation of Small Angle X-ray scattering (SAXS), the shape and size of the particles in the samples were assessed. It was concluded that the particles shape within the nanofibers and the films were globular, with the radius of gyration of 8.5 nm for the nanofibers and 16.5 nm for the films. The nanofiber mat showed less light transparency when compared with the film. This phenomenon could be attributed to the difference in the physical shape, as well as scattering of the light by the voids or particles within the nanofibers.  相似文献   

The effects of density, light and shelter on the growth and survival of African catfish (Clarias gariepinus Burchell, 1822) fingerlings     

Mostafa A. R. Hossain  Malcolm C. M. Beveridge  Graham S. Haylor 《Aquaculture (Amsterdam, Netherlands)》1998,160(3-4):251-258

The effects of stocking density, light and shelter on the growth and survival of Clarias gariepinus fingerings was evaluated. In this experiment African catfish with initial individual mean weight 0.79±0.1 g were reared at two different stocking densities—5 fish l⁻¹ and 10 fish l⁻¹ in either sheltered or unsheltered tanks with reduced and normal light condition. In all conditions growth rate was significantly affected by stocking density. The growth rate was significantly higher at low densities and in reduced light conditions where shelter was provided. Survival rate was in excess of 79% in all treatments and was not affected by treatment.  相似文献   

Effect of sex and rearing system on the quality and mineral content of fiber from raeini cashmere goats     

Mehrdad Shamsaddini-Bafti  Mahnaz Salehi  Ali Maghsoudi  Ali Mostafa Tehrani  Farhad Mirzaei  Syed Mojtaba Syed Momen 《畜牧与生物技术杂志(英文版)》2012,3(3):160-165

The aim of this study was to compare the quality characteristics and mineral content of the fiber from male and female cashmere goats raised under different management systems. Male and female Raeini cashmere goats (<1.5 years of age, n = 48) were selected from flocks raised at a government breeding station or raised commercially under either rural or nomadic conditions. The staple length, cashmere fiber diameter, coefficient of variation for fiber diameter, percentage of cashmere in a fleece, percentage of guard hair in a fleece and cashmere tenacity averaged 4.6 ±0.1 cm, 18.0 ±0.1 m, 20.9 ± 0.4%, 66.1 ± 1.5%, 33.8 ± 1.5% and 1.8 ± 0.2 gf/tex, respectively. The sulfur, copper and zinc content of the cashmere averaged 2.8 ± 0.1%, 0.00065 ± 0.00002% and 0.01276 ± 0.00025%, respectively. Rearing method significantly affected staple length, coefficient of variation of fiber diameter, cashmere tenacity and copper content. Males had a higher coefficient of variation of fiber diameter and cashmere tenacity than females (P < 0.05).  相似文献   

Over-mature beech trees (Fagus orientalis Lipsky) and close-to-nature forestry in northern Iran     

Mostafa Moradi  Mohammad R. Marvie Mohadjer  Kiomars Sefidi  Mahmoud Zobiri  Ali Omidi 《林业研究》2012,23(2):289-294

Oriental Beech is the most important commercial tree species in northern Iran. In recent years wood production companies interested in felling large beech trees for profit have challenged advocates of close-to-nature silviculture who favor conservation. Our study objective was to assess the economic value of over-mature beech trees by relating tree diameter (DBH) to amount of decay. Based on the location of onset of decay, we categorized three types of decay as stump, stem, and crown decay. Trees of greater diameter (age) typically showed greater decay in the stem. Percent of decayed volume, diameter of decayed tissue, and length of decay in tree stems varied between 0.5%?64.3%, 15 cm?75 cm, and 2.0?19.5 m, respectively. With increasing trunk diameter, the proportion of truck decay increased. Red heart and dark red heart constituted 25% and 14.3% of sampled trees, respectively. However, we found no correlation between intensity of stem decay and morphological characteristics of trees. Seedlings were not abundant around the bases of over-mature trees, suggesting that the trees did not contribute to regeneration of the stand. Beech trees of diameter >1 m do not provide valuable round wood for industries and cause to raise wood production costs. We recommend that these trees >1 m DBH should be retained in forest stands because of their low commercial value but high ecological and conservational values such as maintaining biodiversity in forest ecosys-tems.  相似文献   

Evaluating irrigation performance in a Mediterranean environment     

I.?J.?Lorite  L.?MateosEmail author  E.?Fereres 《Irrigation Science》2004,23(2):85-92

Characterizing water use and management in irrigated agriculture is a prerequisite for conserving agricultural water. We carried out a detailed analysis of irrigation performance by documenting the water use of about 840 parcels in an irrigation scheme (Genil–Cabra irrigation scheme; GCIS) located in Andalusia, southern Spain, from 1996 to 2000. Performance indicators based on the water balance detected two water-management strategies, depending on the crop: (1) cotton, garlic, maize and sugar beet had average ratios of measured irrigation supply to the simulated optimum demand (ARIS) ranging between 0.73 and 0.91 and (2) winter cereals, sunflower and olive had a much lower average ARIS (with a 4-year average of 0.28–0.39). We found a large variability in water usage among the management units in all cases. For instance, in cotton, even though the average ARIS was around 0.8, about 50% of the fields were not irrigated adequately (41% with deficit, 9% with excess). Water productivity (WP) in the GCIS was highest for the horticultural crops (garlic, olive; from 1.13 €/m³ to 6.52 €/m³) while it varied among the field crops, being lowest in maize (4-year average of 0.28 €/m³) and highest in sugar beet (4-year average of 1.04 €/m³). Large year-to-year variations in WP were observed in all crops, particularly in sunflower and garlic due either to fluctuating prices for garlic or to the effects of the 1998/1999 drought for sunflower. In fact, WP was lowest in all crops in that year, because seasonal irrigation depths were much higher than in the other 3 years. The combination of ARIS and other performance indicators allowed for determining performance levels and improvement measures. It was found that if more irrigation water is used in the GCIS, garlic and olive will be the crops that profit most from the additional supply. However, it was concluded that, given the wide range in water use and management encountered at the parcel level, improvement policies at the scheme level should always consider individual performance when designing measures for water conservation in irrigated agriculture.  相似文献   

Sunflower Response to Application of L-Ascorbate Under Thermal Stress Associated with Different Sowing Dates     

El-Bially  Mohamed E.  Saudy  Hani S.  El-Metwally  Ibrahim M.  Shahin  Mostafa G 《Gesunde Pflanzen》2022,74(1):87-96

Unlike edaphic factors, it is difficult to control climatic conditions and their changes that affect plant growth and development. To deal with such posture, farmers have to cultivate their crops at the right time. From this point, over two–year of 2014 and 2015, a field experiment was performed at El-Nubaria region, El-Behaira Governorate, Egypt, to assess the response of sunflower to different combinations between sowing dates (early, mid and delayed) and ascorbic acid treatments (with ascorbic acid and without ascorbic acid). Ascorbic acid was sprayed at 30, 40 and 50 days after sowing. The results showed that sowing sunflower in mid sowing (May 21) achieved the highest values of cumulative heat units utilization efficiency as well as all growth and yield traits, while the lowest values were recorded under the delayed sowing date (June 21). Application of ascorbic acid was effective for promoting growth and yield traits under all studied sowing dates. Ascorbic acid achieved 11.6, 10.1, 10.7 and 12.9% increases under early sowing, and 9.5, 6.6, 8.6 and 10.3% increases under delayed sowing in head diameter, seed weight plant^?1, seed yield and oil yield, respectively. Comparing to mid sowing?×?without ascorbic acid, application of ascorbic acid alleviated seed yield losses associated early sowing from 15.7–6.6% and from 23.0–16.4% with delayed one. In conclusion, for remediating the thermal stressful impacts of early or late sowing of sunflower, farmers are advised to treat crop plants with ascorbic acid to avoid yield losses.

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Interaction of methyl nitrite with the inorganic and organic fractions of soils     

A. M. T. MAGALHÃES  P. M. CHALK 《European Journal of Soil Science》1989,40(2):349-358

The reactions of methyl nitrite (CH₃ONO), a gaseous product of NO^?₂ decomposition in soils, were studied by exposure of soils in closed vessels to the gas. The N transformations occurring in soils at different soil-water states were assessed by measuring CH₃ONO and other gaseous forms of N in the gas space, soil inorganic N (NH₄⁺, NO^?₂, NO₃^?) and incorporation of CH₃O¹⁵NO into the soil organic N fraction. The initial rate of uptake of CH₃ONO increased with decreasing soil-water content, but the rate of hydrolysis decreased as soil-water content decreased below – 33kPa matric potential. Uptake was not affected by y-irradiation of soils. Adsorption isotherms conformed to the Langmuir equation in each of 22 oven-dry soils studied. Langmuir adsorption maxima were positively correlated with the clay contents of the soils, and adsorption was reversible to some extent at all soil-water states. Small amounts of added CH₃ONO were recovered as N₂ and N₂O and as ¹⁵NH₄⁺ in γ-irradiated soils. From 60 to 72% of added CH₃O¹⁵NO was recovered by Kjeldahl digestion; this was indicative of a chemical reaction with soil organic matter. The results suggest that the physical process of adsorption of CH₃ONO by clay minerals and the chemical fixation of CH₃ONO by soil organic matter are key factors controlling the atmospheric concentration of CH₃ONO, and that the combined effect of these processes, together with hydrolysis in the soil solution, will inhibit the emission of CH₃ONO formed in N-fertilized soils.  相似文献   

Growth of Vicia faba as affected by inoculation with vesicular-arbuscular mycorrhizae and Rhizobium leguminosarum bv. viceae in two soils     

Y. Z. Ishac  J. S. Angle  M. E. El-Borollosy  M. E. El-Demerdash  M. I. Mostafa  C. N. Fares 《Biology and Fertility of Soils》1994,17(1):27-31

We studied the turnover of interlayer NH _inf4 ^sup+ in three soils cropped with sugar beet. The three soils chosen for this study (Carpi, Cadriano, and Ozzano) are typical of the soils in the Po Valley where sugar beet is grown. The variation in interlayer NH _inf4 ^sup+ content during the growing season was significant and very similar for the Carpi and Cadriano soils, while there was no significant variation in the NH _inf4 ^sup+ content in the Ozzano soil during the same period. The turnover of interlayer NH _inf4 ^sup+ in the Carpi and Cadriano soils was high, and appeared to cover a substantial amount of the N requirement of the crop. The turnover in these two soils showed a significant decrease during the initial phase followed by a period during which the pool of interlayer NH _inf4 ^sup+ was replenished and reached the initial levels again. The spatial distribution of the root system, the pattern of N uptake by the sugar beet crop, and the processes of immobilization-mineralization of organic N all have an influence on the mechanisms of adsorption and release of interlayer NH _inf4 ^sup+ . The release of interlayer NH _inf4 ^sup+ , and thus its availability for plant uptake, was greater at the beginning of the growing season. The physicochemical characteristics of the soils, the K concentration, and the types of clay minerals present were found to be important in determining the dynamics of interlayer NH _inf4 ^sup+ turnover of soils.  相似文献